interface FieldDefinitionInterface

Defines an interface for entity field definitions.

An entity field is a data object that holds the values of a particular field for a particular entity (see \Drupal\Core\Field\FieldItemListInterface). For example, $node_1->body and $node_2->body contain different data and therefore are different field objects.

In contrast, an entity field *definition* is an object that returns information *about* a field (e.g., its type and settings) rather than its values. As such, if all the information about $node_1->body and $node_2->body is the same, then the same field definition object can be used to describe both.

It is up to the class implementing this interface to manage where the information comes from. For example, field.module provides an implementation based on two levels of configuration. It allows the site administrator to add custom fields to any entity type and bundle via the "field_storage_config" and "field_config" configuration entities. The former for storing configuration that is independent of which entity type and bundle the field is added to, and the latter for storing configuration that is specific to the entity type and bundle. The class that implements "field_config" configuration entities also implements this interface, returning information from either itself, or from the corresponding "field_storage_config" configuration, as appropriate.

However, entity base fields, such as $node->title, are not managed by field.module and its "field_storage_config"/"field_config" configuration entities. Therefore, their definitions are provided by different objects based on the class \Drupal\Core\Field\BaseFieldDefinition, which implements this interface as well.

Field definitions may fully define a concrete data object (e.g., $node_1->body), or may provide a best-guess definition for a data object that might come into existence later. For example, $node_1->body and $node_2->body may have different definitions (e.g., if the node types are different). When adding the "body" field to a View that can return nodes of different types, the View can get a field definition that represents the "body" field abstractly, and present Views configuration options to the administrator based on that abstract definition, even though that abstract definition can differ from the concrete definition of any particular node's body field.

Hierarchy

• interface \Drupal\Core\TypedData\ListDataDefinitionInterface; interface \Drupal\Core\Cache\CacheableDependencyInterface
  • interface \Drupal\Core\Field\FieldDefinitionInterface

File

core/lib/Drupal/Core/Field/FieldDefinitionInterface.php, line 51

Namespace

Drupal\Core\Field

Members

Name	Modifiers	Type	Description
CacheableDependencyInterface::getCacheContexts	public	function	The cache contexts associated with this object. Overrides CacheableDependencyInterface::getCacheContexts
CacheableDependencyInterface::getCacheMaxAge	public	function	The maximum age for which this object may be cached. Overrides CacheableDependencyInterface::getCacheMaxAge
CacheableDependencyInterface::getCacheTags	public	function	The cache tags associated with this object. Overrides CacheableDependencyInterface::getCacheTags
DataDefinitionInterface::addConstraint	public	function	Adds a validation constraint.
DataDefinitionInterface::createFromDataType	public static	function	Creates a new data definition object.
DataDefinitionInterface::getClass	public	function	Returns the class used for creating the typed data object.
DataDefinitionInterface::getConstraint	public	function	Returns a validation constraint.
DataDefinitionInterface::getConstraints	public	function	Returns an array of validation constraints.
DataDefinitionInterface::getDataType	public	function	Returns the data type of the data.
DataDefinitionInterface::getDescription	public	function	Returns a human readable description.
DataDefinitionInterface::getLabel	public	function	Returns a human readable label.
DataDefinitionInterface::getSetting	public	function	Returns the value of a given setting.
DataDefinitionInterface::getSettings	public	function	Returns the array of settings, as required by the used class.
DataDefinitionInterface::isComputed	public	function	Determines whether the data value is computed.
DataDefinitionInterface::isList	public	function	Returns whether the data is multi-valued, i.e. a list of data items.
DataDefinitionInterface::isReadOnly	public	function	Determines whether the data is read-only.
FieldDefinitionInterface::getConfig	public	function	Gets an object that can be saved in configuration.
FieldDefinitionInterface::getDefaultValue	public	function	Returns the default value for the field in a newly created entity.
FieldDefinitionInterface::getDefaultValueCallback	public	function	Returns the default value callback for the field.
FieldDefinitionInterface::getDefaultValueLiteral	public	function	Returns the default value literal for the field.
FieldDefinitionInterface::getDisplayOptions	public	function	Returns the default display options for the field.
FieldDefinitionInterface::getFieldStorageDefinition	public	function	Returns the field storage definition.
FieldDefinitionInterface::getName	public	function	Returns the machine name of the field.
FieldDefinitionInterface::getTargetBundle	public	function	Gets the bundle the field is attached to.
FieldDefinitionInterface::getTargetEntityTypeId	public	function	Returns the ID of the entity type the field is attached to.
FieldDefinitionInterface::getType	public	function	Returns the field type.
FieldDefinitionInterface::isDisplayConfigurable	public	function	Returns whether the display for the field can be configured.
FieldDefinitionInterface::isRequired	public	function	Returns whether the field can be empty. Overrides DataDefinitionInterface::isRequired
FieldDefinitionInterface::isTranslatable	public	function	Returns whether the field is translatable.
ListDataDefinitionInterface::createFromItemType	public static	function	Creates a new list data definition for items of the given data type.
ListDataDefinitionInterface::getItemDefinition	public	function	Gets the data definition of an item of the list.